With the continuous increasing of the scale for the integrated circuits and the reduction of the size for devices, three-dimensional device has become the direction of semiconductor industry in the future development. Devices with FinFET structures have received many concerns for their excellent cut-off performance, extendibility, and compatibility with conventional manufacturing technology.
Fin structure has also been introduced into flash memory devices in the development of semiconductor technology currently. A flash memory device is a device to write and erase data electrically, and has two capacitors connected in series achieved by forming dielectric layers which form between a control gate, a floating gate, and a substrate. Those capacitors enable the floating gate to keep charges even when the electricity supply is cut off.
However, it remains impossible for the current process of the Fin-type flash memory device to compatible with FinFET logic device.